EDEM Simulation Run Time
Often the time it takes to get results is the number one most significant factor in determining the feasibility of running any simulation.
Reducing time taken doesn’t necessarily mean faster solver speed or faster processors (although of course these things do help). If we plan our projects and make the appropriate assumptions we can get answers within the required time-frame.
Can we model every grain of dust in a mine? No. Can we cut the model down to a few square meters of material, calibrate appropriately to remove the necessity to model the fines/dust and check our designs with a range of operating conditions? Yes.
Images courtesy VR Steel – The reality is we can’t model all the dust and fines but with an appropriate material model different designs can be analysed. As per the image on the right, the material model is suitable to answer the design questions without needing to be overly complicated.
Too often we see simulations set-up that will take an unfeasible amount of time to complete, some initial time planning can ensure that the run times are within reasonable expectations and project deadlines can be hit.
How do we know if our simulation is going to take 1 hour or 1 day or 1 week? The factors that impact the run time are:
- Time-Step size (usually the Rayleigh Time-Step). Primarily influenced by:
- Particle Size
- Particle Density
- Particle Shear Modulus
The time-step, or calculation cycle, is a fixed value per simulation/material model. The forces acting on each particle are calculated for every cycle. The size of the time-step is critical in that it has to be small enough to ensure stability but large enough to be able to obtain results in a reasonable time.
- Time it takes your CPU to calculate 1 time-step. Influenced by:
- Number of Particles
- Hardware
- Licenses
The number of particles influence the time in an (almost) linear way, double the number of particles = double the calculation time. The quicker your computer can calculate the faster you get your results.
The ability to plan our work and estimate simulation run time is therefore a very important step in any DEM simulation project, the Altair Script and Knowledge library has an estimating simulation runtime spreadsheet and post to aid in EDEM simulation project planning.
Related :
- EDEM Benchmarks
- Particle Shear Modulus
- EDEM Particle Simulation: CUDA GPU and Precision Modes
- How to select a GPU (Graphics Processing Unit) for EDEM
- 10 Common Questions about EDEM GPU Answered
- Estimating EDEM simulation run time
To get started with EDEM: